scholarly journals Adiabatically Correcting an Eddy-Permitting Model Using Large-Scale Hydrographic Data: Application to the Gulf Stream and the North Atlantic Current

2004 ◽  
Vol 34 (4) ◽  
pp. 701-719 ◽  
Author(s):  
Carsten Eden ◽  
Richard J. Greatbatch ◽  
Claus W. Böning
Keyword(s):  
North Atlantic ◽  
Gulf Stream ◽  
Large Scale ◽  
North Atlantic Current ◽  
Hydrographic Data ◽  
The North ◽  
Data Application ◽  
The North Atlantic ◽  
Atlantic Current

scholarly journals Instability-Driven Benthic Storms below the Separated Gulf Stream and the North Atlantic Current in a High-Resolution Ocean Model

2018 ◽  
Vol 48 (10) ◽  
pp. 2283-2303 ◽  
Author(s):  
René Schubert ◽  
Arne Biastoch ◽  
Meghan F. Cronin ◽  
Richard J. Greatbatch
Keyword(s):  
Energy Transfer ◽  
High Resolution ◽  
Kinetic Energy ◽  
North Atlantic ◽  
Gulf Stream ◽  
Eddy Kinetic Energy ◽  
North Atlantic Current ◽  
The North ◽  
The North Atlantic ◽  
Atlantic Current

AbstractBenthic storms are important for both the energy budget of the ocean and for sediment resuspension and transport. Using 30 years of output from a high-resolution model of the North Atlantic, it is found that most of the benthic storms in the model occur near the western boundary in association with the Gulf Stream and the North Atlantic Current, in regions that are generally collocated with the peak near-bottom eddy kinetic energy. A common feature is meander troughs in the near-surface jets that are accompanied by deep low pressure anomalies spinning up deep cyclones with near-bottom velocities of up to more than 0.5 m s−1. A case study of one of these events shows the importance of both baroclinic and barotropic instability of the jet, with energy being extracted from the jet in the upstream part of the meander trough and partly returned to the jet in the downstream part of the meander trough. This motivates examining the 30-yr time mean of the energy transfer from the (annual mean) background flow into the eddy kinetic energy. This quantity is shown to be collocated well with the region in which benthic storms and large increases in deep cyclonic relative vorticity occur most frequently, suggesting an important role for mixed barotropic–baroclinic instability-driven cyclogenesis in generating benthic storms throughout the model simulation. Regions of the largest energy transfer and most frequent benthic storms are found to be the Gulf Stream west of the New England Seamounts and the North Atlantic Current near Flemish Cap.

33.—A Review of the Branching of the Gulf Stream System

1972 ◽  
Vol 72 (1) ◽  
pp. 341-349 ◽  
Author(s):  
C. R. Mann
Keyword(s):  
North Atlantic ◽  
Gulf Stream ◽  
Good Evidence ◽  
Water Masses ◽  
North Atlantic Current ◽  
The North ◽  
Dynamic Computation ◽  
Stream System ◽  
The North Atlantic ◽  
Atlantic Current

SynopsisThe surveys of temperature and salinity that have led to the concept that the Gulf Stream splits into branches are reviewed, beginning with the survey made by Helland-Hansen on board the Michael Sars in 1910. The system of currents, or branches, between the Newfoundland Banks and the Mid- Atlantic deduced by the different investigations from charts of temperature, or by dynamic computation, are not all compatible. There is good evidence that part of the Gulf Stream turns south-east after passing the Newfoundland Banks and part turns north to become the North Atlantic Current. Both these currents are boundaries between water masses in the upper layer of the ocean. The evidence for permanent currents other than these two is conflicting.

scholarly journals ON THE STRUCTURE OF THE NORTH ATLANTIC CURRENT IN MAY – JUNE 1990

2019 ◽  
Vol 47 (2) ◽  
pp. 33-63 ◽  
Author(s):  
Yu.A. Ivanov ◽  
V.I. Byshev ◽  
Yu.A. Romanov ◽  
A.N. Sidorova
Keyword(s):  
Ocean Circulation ◽  
North Atlantic ◽  
Large Scale ◽  
North Atlantic Current ◽  
Shirshov Institute ◽  
North East ◽  
The North ◽  
Southern Branch ◽  
The North Atlantic ◽  
Atlantic Current

“In the last quarter of the ХХ-th century, our country has implemented several major programs of experimental research of the World ocean. Among them, a special place was occupied by the huge in its scale and scientific significance the project SECTIONS aimed at studying the climatic interaction of the ocean and atmosphere. Currently, systematic research in this field has gained new momentum through regular Hydrophysical monitoring of the energy-active region in the North Atlantic in the annual expeditions by Shirshov Institute of Oceanology of RAS (Gladyshev et al., 2017). The results of some special Russian ocean expeditions of the past years, one of which is described for the first time in this article, can serve as a certain historical background for modern studies of the ocean climate evolution”. In 1990 Russian oceanographers carried out a comprehensive hydrophysical study of the Newfoundland energy-active zone in the Northern Atlantic ocean, as part of the national project “Sections” included in the international program WOCE. Three research vessels (R/V) of the Shirshov Institute of Oceanology (SIO): “Vityaz“(cruise 19), “Professor Stockman“( cruise 26) and “Academician Kurchatov“ (cruise 50) together with additional 4 vessels of other institutions were engaged in the field study. Scientific management for general programme of the expedition, dubbed “ATLANTEX-90”, was carried out by Professor Yu. A. Ivanov. The main objective of the program was to study the space-time short-period variability of water dynamics in the large – scale ocean circulation system of Gulfstream–North Atlantic Current. To this aim, in May–June 1990 R/V “Academician Kurchatov” performed several sections crossing the main hydrological fronts of the Newfoundland energy-active zone (45–53°N., 36–45°W). Observations were conducted using the cable probe with sensors of temperature, conductivity and pressure (CTD) and expendable bathythermograph (XBT). All this equipment was special made and passed metrological certification in the design Bureau of Oceanological Engineering (BOE) of SIO. The equipment metrology fitted in whole with international standards at that time. The sea surface temperature (SST) was recorded along the RV route as well. The current velocity was measured during about one month at 14 moorings deployed on a section along meridian 36°W, from 47 to 53°N. The measurements were conducted using electronically operated current meters of POTOK type of the BOE of SIO production. The meters were installed on the each mooring at the horizons of 100, 200, 1000, 2000, 3500 m. In addition to the data of own measurements, facsimile maps of SST from the nearest hydrometeorological observatories were received by radio communication channel during the whole period of observations. Analysis of the obtained data showed that during the field study period the North Atlantic Current (NAC) divided into two branches (Central and Southern) roughly in the neighborhood of 47.5–48°N, where isobath 4500 m turned to the East at right angle to isobath 4000 m. After point of the bifurcation, the Central branch initially maintained a Northerly direction, then turned North-West along the isobath of 4000 m, and farther, turning East, crossed the meridian of 36°W between 51° and 52°N. Prior that stage, the Central branch sometimes approached the meridian 36°W at about 50°N, then deviated to the North–Northwest and finally turned North-East about 51,5°N. The Southern branch of NAC after a split of the main NAC flow followed approximately to isobath 4500 m, and crossed the meridian of 36°W at about 48°North latitude. East of 36°W it could be at times of East-North-East direction, but usually this branch unfolded to the South-South-West, forming the high ridge of the ocean surface dynamic height on the Eastern flank of the NAC. Three return flows were observed in the section of 36°W. One of the flows is marked between the Central and Southern branches of the NAC, while the other two were recorded on the Northern and Southern edges of the section. This structure of the velocity field in fact remained unchanged through all June 1990. The basic zonal flow was observed in the entire water column within the depths from 100 m to 3500 m. The highest current speeds were typical for the upper part of this layer. At depths of 1000–2000 m the velocities were noticeably weakened, increasing again in some places near the bottom. The distribution of meridional components of flow speed according to the measurements on the buoys allowed us to detect the presence of large-scale divergence, which was located along the section on 36°W. Direction of the meridional component of the current to the North and South of 49°N turned out to be the opposite, forming that divergence in the field of the velocity. Under the analysis of the observations it was taken into account that an important role in the formation of the structure of ocean circulation in the area of research could play a seamount (>2600 m), registered by the sounders of R/V “Academician Kurchatov” near 49°N, 36°W. The results of measurements and calculations showed that the average over the entire observation period water transport of the Central branch of NAC through the 36°W section accounted for 62.4 Sv. This value is comparable to the transfer of NAC, assessed four years later by Lazer (1994) 50±23 Sv for approximately the same area where we conducted our work in 1990. Approximately the same average transfer (46,5 Sv) was found in two return flows (presumably North and South recirculations of the NAC Southern branch). In whole, the average water transport in the Eastern direction through the section on 36°W was as high as 111 Sv., and it was 60.9 Sv after subtracting reverse fluxes.

scholarly journals Observed variability of the North Atlantic Current in the Rockall Trough from four years of mooring measurements.

2020 ◽  
Author(s):  
Loïc Houpert ◽  
Stuart A. Cunningham ◽  
Neil J Fraser ◽  
Clare Johnson ◽  
N. Penny Holliday ◽  
...  
Keyword(s):  
North Atlantic ◽  
North Atlantic Current ◽  
The North ◽  
Rockall Trough ◽  
The North Atlantic ◽  
Atlantic Current

scholarly journals The recent AMOC variability in the Subpolar Gyre: results across the OVIDE section

2020 ◽  
Author(s):  
Pascale Lherminier ◽  
Herlé Mercier ◽  
Fiz F. Perez ◽  
Marcos Fontela
Keyword(s):  
North Atlantic ◽  
Lower Limb ◽  
Deep Convection ◽  
Labrador Sea ◽  
Subpolar Gyre ◽  
North Atlantic Current ◽  
The North ◽  
Subarctic Front ◽  
The North Atlantic ◽  
Atlantic Current

<p><span>According to the subpolar AMOC index built from ARGO and altimetry, the AMOC amplitude across the OVIDE section (from Greenland to Portugal) was similar to that of the mid-1990s between 2014 and 2017, i.e. 4-5 Sv above the level of the 2000s. It then returned to average values in 2018. The same index computed independently from the biennial summer cruises over 2002-2018 confirms this statement. Interestingly, despite the concomitant cold and fresh anomaly in the subpolar Atlantic, the heat flux across OVIDE remains correlated with the AMOC amplitude. This can be explained by the paths taken by the North Atlantic Current and the transport anomalies in the subarctic front. In 2014, the OVIDE section was complemented by a section from Greenland to Newfoundland (GA01), showing how the water of the lower limb of the AMOC was densified by deep convection in the Labrador Sea. The spatial patterns of volume, heat, salt and oxygen transport anomalies after 2014 will be discussed at the light of the 2000s average.</span></p>

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